FAN8902 is a monolithic integrated circuit designed by Fairchild Semiconductor Corporation for the PWM control of a DC fan motor current in an automotive system. It allows the fan motor speed to be controlled linearly and efficiently.
The FAN8902 (KA3902) from Fairchild Semiconductor is a monolithic integrated circuit designed for PWM control of DC fan motor current in automotive applications. It provides linear speed control, low supply current, and multiple built‑in protection functions such as over‑voltage, over‑current, load‑dump, thermal shutdown, and under‑voltage lockout.
The datasheet includes pin assignments, an internal block diagram, absolute maximum ratings, electrical characteristics, and application notes covering UVLO, current sensing, thermal shutdown, oscillator component selection, slope compensation, and motor stall current limitation.
| Supply Voltage (VCC) | 9.0 V – 32.0 V |
|---|---|
| Peak Output Current | 0.8 A |
| Power Dissipation | 1 W |
| Operating Temperature | -40 °C – +90 °C |
| Start‑up Current (Ist) | 1.0 mA – 1.5 mA |
| Operating Supply Current | 6.0 mA – 8.0 mA |
The device operates from –40 °C to +90 °C.
It supports a supply voltage from 9 V (minimum) up to 32 V (maximum), with a typical value of 12 V.
The chip includes over‑voltage, over‑current, load‑dump, thermal shutdown, and under‑voltage lockout protection.
The FAN8902 limits stall current through its built‑in stall current limitation circuit described in the application information section.